SYNTHESIS AND PHOTOPHYSICAL PROPERTIES OF Zr AND Hf PHTHALOCYANINES WITH OUT-OF-PLANE COORDINATED CHALCONES

Abstract

Zr(IV) and Hf(IV) phthalocyanines with chalcone-derived out-of-plane ligands were synthesized and characterized by standard spectroscopic methods. The complexes combine two chromophores, enabling interchromophore interactions that strongly depend on solvent polarity. In toluene, the fluorescence excitation spectra closely follow absorption and include the ligand band, indicating efficient excitation energy transfer to the phthalocyanine core. In acetonitrile, the ligand contribution is weak, consistent with the drastic drop in fluorescence quantum yield of the free ligand (0.2500 → 0.0036). These results reveal pronounced solvent-sensitive photophysical behavior, suggesting that such dual-chromophore phthalocyanines are promising for applications in solar-driven photocatalysis.